1. Field of the Invention
The present invention relates to data storage control apparatus and method which perform a data writing process and a data reading process for a storage medium.
2. Related Background Art
In recent years, a multifunctional peripheral (MFP) such as a digital multifunctional apparatus having plural functions, e.g., a copying function, a facsimile (FAX) function, a printer function, a scanner function and the like became widespread. Such the apparatus has been developed in a style that a conventional monofunctional apparatus is added with another function. For example, a copying machine added with the FAX function, a FAX machine added with the printer function have been developed.
Therefore, the MFP having such the plural functions as above uses an image data memory and a system memory for each function. For example, in the copying function (including later-described electronic sort function), a memory for storing the image data to be subjected to copying rotation and image reduction layout, a memory for storing the image data to be used for an electronic sorter, and a hard disk (HD) are used. In the FAX function, a memory for performing memory transmission, memory reception and a printing image rotation process, and an HD are used. In the printer function, a memory for storing the image data to be subjected to spooling (i.e., simultaneous peripheral operation online) of PDL (page description language) data and electronic sort printing, and an HD are used. In the scanner function, a memory for storing all documents on a feeder, and an HD are used.
As above, in the conventional MFP, since the image data memory and the system memory are provided for each function, there has been a problem that the cost of the MFP increases according to the prices of lots of memories.
Therefore, in order to improve such a conventional state, it has been thought that the plural memories are made common to the plural functions.
However, if the structure that the required image data memory and the required system memory are common to the respective functions of the MFP is applied, it is necessary to construct the memory with a high-speed random access memory (RAM) to obtain satisfactory writing/reading speed for the memory used in each function of the MFP. Further, to store a large-capacity document, the large-capacity high-speed RAM is necessary. Thus, there is a problem that the cost of the system increases.
Further, if the structure that the required image data memory and the system memory common to each function of the MFP are provided with low-cost storage media such as HD""s is applied, since it is impossible to obtain the satisfactory writing/reading speed for the memory used in each function of the MFP, there is a problem that system productivity deteriorates.
In recent years, there has been a digital copying machine having a large-capacity HD. Such the large-capacity HD is used to mainly execute an electronic sort function.
The electronic sort function is to read the images of all the originals to be copied, store the image data obtained from the read images in the HD, repeatedly read the image data in the order of page, and print out the read data. Thus, even if the copying machine does not have a mechanical sorter including plural bins, it is possible to discharge copying paper sheets in a sorted state.
Further, a mailbox function has been proposed in recent years. The mailbox function is to divide the storage area of the HD into plural areas each corresponding to each user, once store the image data received from a host computer at the area (i.e., mailbox) indicated by the host computer, and print out the image data from the mailbox. If the user inputs from an operation unit a password to access his own area, the image stored in the corresponding mailbox is printed out. Thus, since the image in the mailbox of one user can not be printed out by the copying machine without his permission, there is no fear that the image data in the mailbox of one user is viewed by the other users.
Further, a form synthesis function has been proposed. The form synthesis function is to previously store in the HD plural form images (i.e., tables and illustrations) as registration images, synthesize or composite the form image and an image read by the scanner, and print out the synthesized image.
In the digital copying machine having such the plural functions as above, a general-purpose HD ordinarily used in a computer or the like is used.
The general-purpose HD applies a zone bit recording system. Hereinafter, the zone bit recording system will be explained with reference to FIG. 26. The disk of the HD is divided into 16 to 20 areas in accordance with its recording density, and each area is called a zone. In this system, the quantity of the data stored at the outer circumference (i.e., zone 0 side) of the disk is made larger than that of the data stored at the inner circumference (i.e., zone 15 side) thereof. Therefore, processing speed in case of accessing the outer circumference is higher than that in case of accessing the inner circumference.
For this reason, in order to obtain access speed according to the process such as the electronic sort function in which it is required to perform the operations in real time, the digital copying machine uses only the outer circumference of the HD at which access speed is high because of the zone bit recording system.
However, since the digital copying machine having the plural functions including the electronic sort function merely uses only the outer circumference of the HD, efficiency in use of the HD is low. For this reason, in order to perform plural processes, it is necessary to use a HD having a too large capacity or use plural HD""s, thereby increasing the cost.
Further, the general-purpose HD used in the computer or the like provided in such the digital copying machine as above has an automatic power-down function. Hereinafter, the automatic power-down function will be explained with reference to FIG. 34 which illustrates a state transition of the HD.
In the drawing, an active state 3561 is the state that the HD is operating (i.e., being accessed), and an idle state 3562 is the process wait state. Since a spindle motor for rotatively driving the HD is being driven in the idle state 3562, this state can immediately change into the active state 3561. The idle state 3562 is the state that it is possible to immediately start to access the HD. Further, the HD is of course operating in the active state 3561, whereby no time is necessary before the access to the HD starts. A standby state 3563 is the state that the spindle motor completely stops. Further, a sleep state 3564 is the state that the spindle motor completely stops and a power supply also stops.
The above state transition is determined according to standardized commands concerning the HD or specifications peculiar to the HD.
If the access to the HD (i.e., data writing/reading to/from HD) is not performed for a predetermined time, such the general-purpose HD automatically changes its state from the active state 3561 or the idle state 3562 into the standby state 3563, whereby the spindle motor for rotatively driving the HD stops.
However, if it accesses the HD in the standby state, it is necessary to start the spindle motor which has completely stopped. Thus, a time (about 20 seconds) to start the spindle motor is necessary when the access to the HD starts.
For this reason, in case of performing the process such as the electronic sort function in which it is required to perform the operations in real time, if the HD is in the standby state, it is impossible to immediately start the access to the HD, whereby process efficiency is low. Thus, there is some fear that such a drawback influences productivity.
An object of the present invention is to provide a data storage control apparatus and a data storage control method which solved the above problems.
Another object of the present invention is to provide a data storage control apparatus and a data storage control method which can prevent an increase of cost, and can also perform plural processes including the process in which it is required to perform operations in real time, without decreasing productivity.
Still another object of the present invention is to provide a data storage control apparatus and a data storage control method which can increase the productivity in the process in which it is required to perform the processes in real time.